It could well be a software problem. And if it is, they won't admit anything until they are sure of what it is. But this is not a conspiracy of Detroit automakers to wreck Toyota. It could be a conspiracy by Toyota to cover up a problem.
We all know that a car computer is unlikely to cost as much as a laptop to produce, but to replace one costs several times that amount.
I do not understand why anyone would pay $3000 for a built-in navigation device for their car when you can buy a decent one you just plug into the cigarette lighter for under $100 that will do nearly everything the factory unit can do and can be replaced with a new more powerful one for the same money every two years or so. We know that if the one built into the car fails, it will cost several hundred to dig into the dashboard, and thousands more to repair it.
I really doubt that the guy that reported the runaway Toyota will not be charged with anything. I can't imagine what his motive would be, anyway. I have not heard that he is even suing anyone.